My program stops after executing till the first loop. I don't know why?

int main() {
//  Return the index of the catcher who gets the catch, or -1 if no one gets the catch.
int n;
int x;
cin >> n >> x;
vector<int> X(n);
for(int X_i = 0; X_i < n; X_i++){
   cin >> X[X_i];
}

vector<int> V(n);
for(int V_i = 0; V_i < n; V_i++){
   cin >> V[V_i];
}
int result = whoGetsTheCatch(n, x, X, V);
cout << result << endl;
return 0;

} //I tried inserting a line break after first loop but doesn't work and also tried it in several compilers such as c98,99,11.